Novak Djokovic will grapple with his growing rivalry with Andy Murray and the enduring powers of Roger Federer as he bids for the first Australian Open hat-trick of the professional era.
Rafael Nadal's withdrawal through illness has robbed Melbourne Park of a repeat of last year's epic final, when Djokovic finally tamed the Spaniard at 1.40am after a record, five-hour, 53-minute final which left him with bleeding toes.
But the Serbian world number one will face a stiff challenge from the newly assertive Murray, fresh from his first grand slam win and keen to avenge his final and semi-final defeats to Djokovic in Melbourne in 2011 and 2012.
Also pressing hard will be Federer, holder of an unmatched 17 grand slams and still hungry for more even though, at the age of 31, he is conceding six years to his younger rivals.
Murray, the world number three, was thrashed by Djokovic in the 2011 Australian Open decider, and narrowly lost out in their thrilling five-set semi-final last year.
But the Scot then beat Djokovic on his way to London Olympics gold, and again in the US Open final as he became Britain's first male grand slam singles winner since Fred Perry in 1936.
Despite Nadal's absence because of a stomach virus, after a knee injury ruled him out for much of last year, the competing claims of the top three men leave the year's opening grand slam unpredictable.
"I have high ambitions for myself, but I am absolutely aware it is going to be very difficult, because today's men's tennis is very competitive," Djokovic said.
"Andy Murray winning his first grand slam title last year has also got him to this group of players that are serious candidates to win the Australian Open."
Djokovic tuned up for the Australian Open playing for Serbia in the mixed-teams Hopman Cup in Perth, and he said he relished the battles to come at Melbourne Park, where he has won three of his five grand slam titles.
No one has won more than two consecutive Australian Open titles since Roy Emerson completed his run of five in a row in 1967, two years before the advent of professional tennis.
"It is a huge challenge. I love the Australian Open, that court brings out the best memories of my career, the great support I always get there, the night sessions, the day sessions, it is always interesting to play," Djokovic said.
"Every grand slam brings something special to it. The Australian Open is by far my most successful one so I am really looking forward to it. I like the hard court, I like the conditions and I am going to go for the trophy."
Murray, coached by Ivan Lendl and relaxed and confident after breaking his grand slam jinx, comes into Melbourne on the back of his 25th career singles title at the Brisbane International.
"I hope that the Australian Open goes a bit better for me than it did last year," said the two-time finalist. "I played some very good tennis there. I lost a set in the first round, and then won the next four matches in straight sets, until the [semi-final] match with Novak which I played very well."
Murray, who survived some uncomfortable moments to beat Grigor Dimitrov in the Brisbane final, acknowledged he had developed a greater mental edge following his successes in the last half of 2012.
"Obviously, the last few years I got close but never managed to get over the final hurdle," he said of his four previous failures in grand slam finals. "So whether it was a mental thing, whether it was things in my game I needed to improve, physical things, who knows exactly?
"But now that I've managed to do it, I hope that when I'm in those situations again I'll deal with them better and put less pressure on myself, which obviously will help me play better.
"It's a change of mentality really, and that doesn't happen in a few weeks. It's taken time to believe that that's the right thing to do, to be aggressive," he added.
Since Lendl first joined him as coach this time last year, the pair have worked together to hone his game. Lendl lost his first four grand slam finals, as well, before going on to win eight majors.
So Murray is confident that Lendl's guidance will continue to serve him well.
"Having someone like Ivan around me - he went through a similar sort of thing - so that's obviously helped as well," Murray said. "He's given me some advice on how to deal with certain things that come with winning big events."
Murray said it was hard to describe in a few words the difference that Lendl had made to his game.
"We've worked on some minor technical things, some mental things, and we've obviously worked on tactical things as well," he said. "But he tries to keep things fairly simple and not overcomplicate things. That's something that I think especially at the beginning of my career I struggled with."
Meanwhile, four-time winner Federer, keen to extend his long stay at the top of men's tennis, has unusually opted out of playing a warm-up tournament. The Swiss has not reached the Melbourne final since his last win in 2010. "I want to try and make this last as long as I can... I don't want to fizzle out," the world number two said. "I'm confident if mentally I'm fresh, which I feel I am, and physically I am fine, which I am, too, that I will play a good Australian Open. I think it's an exciting one. We had four different grand slam champions last year and everybody seems in great shape. There's not one you could say he's not playing so well except Rafa, who's obviously not playing. I've never played a poor Australian Open, so of course I'm hoping for a similar result.
"I hope to keep on playing for many years, because I love it. I love the pressure of playing with a new generation coming up, who are improving quickly.
"It's part of the puzzle that makes me motivated, trying to play against the likes of Novak, Andy and Rafa."
Federer thinks Djokovic is the favourite at Melbourne Park. "He's probably been the best hard-court player over the last couple of years, even though Murray won the US Open," Federer said. "Andy Murray is playing great and only going to get stronger in the next couple of years."
David Ferrer, who won the most matches (76) and titles (seven) last year, is the fourth seed in Nadal's absence and has a chance to climb above the fourth-ranked fellow Spaniard for the first time in his career.
Agence France-Presse, Associated Press